This Core C will provide a number of essential functions for Projects I-VI of this Program Project. These include the synthesis of peptides that are required by the Projects for biological and biochemical investigations. In addition, the Core will characterize synthetic and novel or modified peptides and proteins by Edman based chemical sequencing and mass spectrometry. Core C will synthesize and characterize peptides, and develop new HPLC- and CZE-based analytical systems to improve resolution and resolution and efficiency. Additionally, this Core will perform circular dichroism (CD) experiments as requested. Using the Merrifield automated SPPS, Core C will synthesize, each year, a total of approximately 10-15 peptides (20-40 residues in length; linear, cyclic, phosphorylated). Using the latest techniques for the preparative purification of peptides/proteins, we will provide 10-100 mg of highly purified peptides to support investigations carried out in most Projects. All peptides will be extensively characterized by the techniques available to the Core, including HPLC, CZE, MS, and Edman degradation. The characterization of novel proteins involved in neuroendocrine regulation is an essential part of this Program. The Core provides both state-of-the-art instrumentation and highly trained investigators and support personnel to carry out these characterizations. The Core will characterize novel peptides, proteins or post-translational modifications of known proteins being studied by Program investigators and in particular, novel CRF-like ligands, the sites of interaction between CRF-like ligands and CRF receptors and binding proteins. The disulfide arrangement in the N-terminal extracellular domain of the CRFR will be determined to facilitate rational mutant design. In addition, we will confirm the covalent structure of recombinant proteins that the Projects generate for use in biological studies.